Controller Area Network (CAN) is a broadcast, differential serial bus standard typically used in the automotive industry. CAN features high immunity to electromechanical noise and arbitration free fixed priority.
STK600 features the ATA6660 CAN transceiver. A male DB9 connector and a 10 pin header is provided for bus connection
If a network termination is needed (CAN baudrate higher than 100 Kb/s), the 'TERM' jumper can be mounted to insert a 120 ohms resistor between CAN-H and CAN-L.
'SLOPE CTRL' is provided to adjust the CAN signal slopes and prevent unsymmetrical transients on the bus lines. The center pin on 'SLOPE CTRL' is connected to the ATA6660 RS pin. This must be held below 0.87·VTG which is the standby threshold voltage for AT6660.
Mount a jumper to either side of 'SLOPE CTRL' to prevent AT6660 from going to standby.
The CAN transceiver is connected to the MCU trough the two-pin (rx and tx) 'CAN' header near the switches on STK600. The target MCU can be any AVR (bit banging or USART), but is more typically one of the AT90CAN series which support the CAN protocol in hardware.